Credit: The Associated Press

In this April 14, 2014 file photo, the chief coordinator of the Joint Agency Coordination Center retired Chief Air Marshal Angus Houston speaks at a press conference about the ongoing search operations for missing Malaysia Airlines Flight 370 in Perth, Australia. Houston has become the global face of the massive monthlong search operation off Australia's west coast to find the missing Boeing 777, which is believed to be resting somewhere on the silt-covered bottom of the Indian Ocean in a patch the size of Los Angeles. (AP Photo/Rob Griffith, File)

PERTH, Australia — He speaks with a calm, steady voice as he tackles question after question in an attempt to explain one of the biggest mysteries the modern world has ever known: What happened to Malaysia Airlines Flight 370?

Angus Houston has become the global face of the massive monthlong search operation off Australia's west coast to find the missing Boeing 777, which is believed to be resting on the silt-covered bottom of the southern Indian Ocean, somewhere in a patch of sea the size of Los Angeles.